Cotton norflurazon

During the summer of 1997, water samples were collected and analyzed for herbicides from 32 Playa Lakes of the High Plains that receive drainage from both cotton and corn agriculture in West Texas (Figure 30.1). The major cotton herbicides detected in the water samples were diuron, fluometuron, metolachlor, norflurazon, and prometryn. Atrazine and propazine also were routinely detected in samples from the Playa Lakes. 

US scientists tested water samples taken from the Mississippi Embayment (Arkansas, Kentucky, Louisiana, Mississippi, Missouri and Teimessee), a major area for cotton production in the United States L Dicrotophos (WHO Ib), an organophosphate used extensively in the cotton growing areas was the most frequently detected (35% of samples) . Methyl parathion (WHO la), the most used insecticide in the cotton growing areas was the second most frequent contaminant (18%). The researchers also found traces of profenofos (12%), malathion (12%), cyanazine (46%), fluometuron (57%), and norflurazon (49%) - all pesticides applied to cotton growing in the region . ... 

The range of action of norflurazon is similar to that of metflurazon, but it is a more potent herbicide. It can be used on cotton, stone fruits and cranberries at a rate of 1-4 kg active ingredient/ha. Its half-life in the soil is 21-28 days. It is susceptible to light. 

According to the investigations of Strang and Rogers (1974) the major factors of the selectiviti of metflurazon and norflurazon are the differences in absorption and translocation. In tolerant cotton the absorbed compounds are accumulated in the roots, while in sensitive soybean and maize significantly more herbicide is translocated to the shoots. 

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